My dear friend, they patched this. Either you, or your ally, or the opponent's you are facing, are not between Ranks 7-8. If you were Rank 7 or 8, or facing a higher Ranked opponent you would be somewhere between 325 points to 350 points. Giving you more than enough to bring your Battlebarge. The game is not broken, you're just not within the correct parameters. I play all the time with my Battlebarge, in 2v2's online... but my 2v2 partner is Rank 8, as am I.

It can be annoying not using your Battlebarge in every fight, but when you take into account it's relative power compared to other Battleships in the game, I think it's fine. Space Marine ships as a whole are more expensive, but quite a bit more powerful - if used properly. It's not unintended, the Battlebarge is worth every point of it's 306 cost.